Many Americans, including far too many physicians, appear to believe that the development of high blood pressure (BP) is largely the result of bad genes, being overweight, growing older, or just bad luck. Far too many MDs give their patients with prehypertension and hypertension (HTN) the impression that salt intake is a minor factor for a few ?salt sensitive? people but for most people the cause of primary HTN is unknown. Of course, given these beliefs it is easy to understand why more than 90% of all Americans end up with HTN and have their MDs stressing the only way to control their BP is by taking drugs that often have adverse side effects. The longest and largest study on the efficacy of a BP drug found that there was only a modest (<15%) reduction in cardiovascular deaths in those taking the drug compared to a placebo. However, having HTN increases the risk of CVD mortality by at least 300%.
A recent study of more than 11 thousand European men and women ages 45-79 examined the association between the amount of sodium in their urine and a genetic trait known to increase the risk of developing HTN. The results showed that this genetic trait, which leads to higher levels of angiotensin II in their blood, was associated with significantly higher BP in those who ate the most salt. However, in those who had the least sodium in the urine having this genetic trait did not appear to increase BP. The authors conclude: Genotype effects in populations at low exposure to sodium are not likely to be seen.?1 This study also found a highly significant association between sodium intake and blood pressure for all genotypes.
Bottom Line:?Genetic factors no doubt make some people more susceptible to the toxic effects of excess dietary salt and so more likely to develop more serious HTN earlier in life. However, it is increasingly clear that a dramatic reduction in the amount of salt added to foods by individuals and particularly the food industry would largely eliminate a disease that is a major risk factor for heart attacks, heart and kidney failure and the #1 risk factor for stroke.
By James J. Kenney, PhD, RD, FACN.
1 Am J Clin Nutr 2008;88:392-7
Stephanie Ronco has been editing for Food and Health Communications since 2011. She graduated from Colorado College magna cum laude with distinction in Comparative Literature. She was elected a member of Phi Beta Kappa in 2008.